The present application relates to an interactive data retrieval system, to display apparatus which is suitable for use in such a system, to a digital recording medium which is suitable for use in such a data retrieval system and data display apparatus, and to a method of recording and displaying a still visual image which can be carried out by such a data retrieval system or display apparatus. The present invention relates particularly but not exclusively to such a system, apparatus, recording medium and method when used to handle color images or manufacturers product literature. For example, it is envisaged that such an electronic library will enable architects, quantity surveyors and others to obtain up to the minute information of the products and services offered to the construction industry by manufacturers and suppliers.
One of the main factors which has inhibited the use of electronic data retrieval systems handling color images has been the slow retrieval and display of such images, even when the images are read from a digital recording medium such as a CD-ROM. The various aspects of the present invention are each directed to increasing the speed and/or resolution with which a recorded image (particularly a color image) can be displayed.